The mum effect – a project member’s reluctance to report bad news about a troubled project – has been recognized as an important contributor to project failure. While there are many potential factors that can influence the mum effect, in this study we focus on two factors that are particularly important in today’s software development environment: (1) the issue of fault responsibility that arises in the context of outsourced IT projects that involve an external vendor, and (2) the issue of time urgency, which has become more important as firms seek to compete on “Internet time,” developing and delivering applications with greater speed than ever before. We draw upon the basic whistle-blowing model adapted from Dozier and Miceli (1985) to examine how fault responsibility and time urgency ultimately affect a project member’s IT project reporting decision. Based on the results of a controlled laboratory experiment, we confirmed that the basic whistle-blowing model holds in an IT project context and found that both fault responsibility and time urgency can have significant effects on an individual’s willingness to report bad news. Fault responsibility exerts both direct and indirect influence on willingness to report bad news, while time urgency was found only to exert an indirect influence on willingness to report bad news. One implication of our study is that when fault responsibility rests with an outside vendor, this can actually increase the probability that a client employee will report the bad news to his or her management, provided that the vendor is not able to hide the problem entirely from the client organization. With respect to time urgency, our results suggest that managers may be able to increase individuals’ willingness to report by emphasizing that there is a narrow window of time to correct defects before a project is delivered and the impacts of defects start to be felt. Contributions and directions for future research are discussed.